I’ve recently installed Solaris 11.4 on a VM and, as soon as I tried to log in remotely using SSH, my connection was refused straight away. First of all, I checked if the service was enabled:
$ svcs ssh STATE STIME FMRI online 13:23:15 svc:/network/ssh:default
I checked SSH directory under /etc and something was definitely not quite right with the auto-generated keys:
-rw------- 1 root root 0 Jan 4 13:23 ssh_host_ed25519_key -rw-r--r-- 1 root root 0 Jan 4 13:23 ssh_host_ed25519_key.pub -rw------- 1 root root 0 Jan 4 13:23 ssh_host_rsa_key -rw-r--r-- 1 root root 0 Jan 4 13:23 ssh_host_rsa_key.pub
The keys were there… but truncated to zero.
Something, somewhere went wrong during the key generation (usually when OpenSSH is run for the first time) so I deleted the keys and restarted the service:
# svcadm restart ssh
The keys were re-generated and I was able to log in.